45

a—9

Between Kirita Bay and where the road descends to the shore-line the rocks at places are dark-blue splintery shales, which near the surface have weathered to light-yellow or buff-coloured rock, characteristic of other parts. On the coast-line the rocks are often more gritty; sometimes thin-bedded and drossy. The sandstones and shales alike abound in veins and nests of calcite. The dip of the different strata is various, but generally easterly or away from the coast-line. Between Waikawau and Mata Creeks a succession of massive dykes of diorite or andesite appears on the coast running sub-parallel thereto, as they cannot be traced far inland, and hence they may not prove so numerous as they appear to be. Between the Mata and the mouth of the Waitapukahu River, better known as Tapu Creek, volcanic rocks appear on the coast-line, and the slates lie a little inland, first appearing at the bridge in the lower part of the gorge of Tapu Creek, less than a mile from the beach. Sandstones predominate, but shales are not absent, and immediately on the south side of the gorge these disappear under heavy beds of coarse volcanic breccia on the inland or east side of their exposure, and rocks of finer grain on the seaward side. The eastern boundary of this area of the Maitai series has not been exactly ascertained, but as determined by four or five traverses from the coast-line to the eastern boundary, it is approximately as shown on the map accompanying this report. The only other outcrops of slate rock met with on the western side of the Peninsula appear at Eocky Point, north of Tararu Creek, near the Thames, and in the middle part of Waihoanga Creek. This has been often described, and shortly, as seen on the beach and in Eocky Point, the lowest rock is a dark-blue slate, stratified, and dipping to the south-west at moderate angles, followed by a light-grey felsite-tuff, of which sufficient and ample description has been given in the various extracts made from the writings of previous workers on this field. The rock is to the best of my knowledge of a sedimentary character, but the reasons put forth by Professor Hutton weigh with me, and I agree to speak of it as a felsite-tuff. The only other area of Maitai rocks met with on the Peninsula is that exposed on the Kuaotunu Peninsula. This lies separate and apart from the nearest outcrop of the same formation at the Tiki, a distance of between ten and eleven miles, and in the intervening space there is such massive and thick developments of volcanic rocks that there is little likelihood of rocks of the older sedimentary series being found in this intervening space. At Kuaotunu these rocks are well exposed on the beach and along the north shore-line of the Peninsula, from fully a mile west of the township to the eastern end of the high cliffs that terminate the northern slopes and outrunning spurs of Black Jack on the Waitaia Eange. Black Jack is a rugged peak rising immediately at the back of Kuaotunu Township, and is formed of rocks belonging to the Maitai series, saturated with siliceous deposits, the result of thermal action. This constitutes the northern peak of the Waitaia Eange, which runs north-north-west and south-south-east across the Peninsula, near its eastern or landward end. Essentially, this range is composed of slates and sandstone belonging to the Maitai series, but towards its southern end volcanic ejectamenta cover up the sedimentary rocks, these and these only are seen at the surface from the trig, station to the shores of Mercury Bay. The eastern boundary of the slates runs from the shore of Kuaotunu Bay south-east to near Brown's camp, on the road from Kuaotunu to Mercury Bay, and thus the area of slates and sandstones is approximately about three miles in length east and west, and somewhat better than two miles broad in a north and south direction. The rocks on the coast-line consist of hard grey sandstones, often with small angular inclusions of slate and bands of sandstone or shale interbedded. At some places, the strike is nearly east and west, but as a rule it is in a northerly direction, and the dip is variable but mostly to the eastward. On the shore-line, though towards the east the rocks in the sea-cliffs are much decomposed, there is no difficulty in recognising these rocks, nor should there be in any part of the area covered by them. Yet where decomposed at the surface they have been mistaken for and described as volcanic rocks. (Vide p. 27.) South of the middle part of the Waitaia Eange a line of auriferous quartz occurs in the Waitaia Mine, trending north-north-east, and others are present in a spur of slate and sandstone country that lies between the two main branches of Kuaotunu Creek. On the principal line of reef are situated the more important mines of the the Kuaotunu district and goldfield. The field was examined in 1893 by Mr. James Park, late Director of the Thames School of Mines. Mr. Park describes the rocks forming the spur between the two branches of the Kuaotunu as being of volcanic origin; but deeper mining and road-cuttings, &c, have shown the true nature of the rock. These slates are surrounded on the east, south, and west by volcanic rocks, and rise to a height of 600 ft., and are generally arranged as a syncline. They show the presence of the middle and lower parts of the series as developed in the Cape Colville Peninsula. The Maitai series cf the Geological Survey classification has its typical development in the Maitai Valley, near Nelson, and thence rocks belonging to the series extend along the western slopes of Dun Mountain Eange to near Top House in the Wairau Valley. In Nelson, the formation consists of sandstones, red and green and dark-blue slaty beds, with a massive development of grey or bluish-grey limestone at the base of the series. Characteristic fossils are found in the limestones, leaving no doubt as to the Carboniferous age of the beds. In the rocks of the Cape Colville Peninsula, referred to the same period, fossils might be expected, but after careful search none have been discovered by me. Mr. Park, however, informs me that he found fossils in these beds at Cabbage Bay, and again at Stony Bay, on the east of the Peninsula, north of Port Charles. Whether these will serve to determine the age of the beds may be considered doubtful, as I could not learn to what genera they belonged. Thin and impure seams of coaly matter or graphite occurs at Kuaotunu, at the eastern end of the sea-cliffs forming the northern slopes of Black Jack, and in the adjacent sandstones scattered fragments of carbonised plants are to be found, but these give no hint of the presence of a well-preserved flora in the neighbouring rocks; and from this paucity of fossil remains, by such evidence, the question of the age ot these older sedimentary rocks on the Peninsula is likely to remain undetermined. Nevertheless,